Method for centralizing interference coordination

ABSTRACT

A method for interference coordination comprises receiving, from a first network node, a reference signal indicating that one or more second network nodes are experiencing interference. The reference signal indicates at least one identifier for the first network node and for the second network nodes. The method further comprises preparing a remote interference management (RIM) coordination message based on the reference signal, and sending, to the first network node, the RIM coordination message to be forwarded to the second network nodes. The method provides a communication between a central aggressor network node and a central victim network node to exchange reference signal and RIM coordination information. Furthermore, the central victim network node may pass the RIM coordination message to a group of victim network nodes indicated in the RIM coordination message.

TECHNICAL FIELD

Particular embodiments relate to the field of interference coordination;and more specifically, to methods and apparatuses for a centralizedinterference coordination.

BACKGROUND

A 5G system comprises multiple function nodes. FIG. 1 illustrates anexample 5G system architecture including the function nodes to carry outdifferent network functions (NFs). The function nodes and their NFs arelisted as followings:

(1) Access and Mobility Management function (AMF) supports: terminationof non-access stratum (NAS) signaling, NAS ciphering and integrityprotection, registration management, connection management, mobilitymanagement, access authentication and authorization, and securitycontext management;

(2) Session Management function (SMF) supports: session management(e.g., session establishment, modification, and release), IP addressallocation and management of user equipment (UE), functions of dynamichost configuration protocol (DHCP), termination of NAS signaling relatedto session management, downlink (DL) data notification, and trafficsteering configuration for user plane function for proper trafficrouting;

(3) User plane function (UPF) supports: packet routing and forwarding,packet inspection, and QoS handling which acts as external PDU sessionpoint of interconnect to Data Network (DN) and is an anchor point forintra- & inter-RAT mobility;

(4) Policy Control Function (PCF) supports: unified policy framework,providing policy rules to CP functions, and access subscriptioninformation for policy decisions in unified data repository (UDR);

(5) Authentication Server Function (AUSF) which acts as anauthentication server;

(6) Unified Data Management (UDM) supports: generation of Authenticationand Key Agreement (AKA) credentials, user identification handling,access authorization, and subscription management;

(7) Application Function (AF) supports: application influence on trafficrouting, accessing network exposure function, and interaction withpolicy framework for policy control;

(8) Network Exposure function (NEF) supports: exposure of capabilitiesand events, secure provision of information from external application to3GPP network, and translation of internal/external information;

(9) NF Repository function (NRF) supports: service discovery functionwhich maintains NF profile and available NF instances; and

(10) Network Slice Selection Function (NSSF) supports: selecting of thenetwork slice instances to serve the UE, determining the allowed networkslice selection assistance information (NSSAI), and determining the AMFset to be used to serve the UE.

Considering interference protection in 5G system networks, wirelesscellular networks are built up of cells, and each cell is defined by acertain coverage area of a radio base station (BS). The BSs communicatewith terminals/UE in the network wirelessly. The communication iscarried out in either paired or unpaired spectrum. In case of pairedspectrum, the downlink (DL) and uplink (UL) directions are separated infrequency, called Frequency Division Duplex (FDD). In case of unpairedspectrum, the DL and UL use the same spectrum, called Time DivisionDuplex (TDD). As the name implies, the DL and UL are separated in thetime domain, typically with guard periods (GP) between them. A guardperiod serves several purposes. Most essentially, the processingcircuitry at the base station (BS) and UE needs sufficient time toswitch between transmission and reception, however, this is typically afast procedure and does not significantly contribute to the requirementof the guard period size. There is one guard period at adownlink-to-uplink switch and one guard period at an uplink-to-downlinkswitch, but since the guard period at the uplink-to-downlink switch onlyneeds to give enough time to allow BS and UE to switch between receptionand transmission, and consequently typically is small, it is forsimplicity neglected in the following description. The guard period atthe downlink-to-uplink switch, GP, however, must be sufficiently largeto allow a UE to receive a time-delayed DL grant scheduling the UL andto transmit the UL signal with a proper timing advance, e.g.,compensating for the propagation delay, such that it is received in theUL part of the frame at the BS. In practice, the guard period at theuplink-to-downlink switch is created with an offset to the timingadvance. Thus, the GP should be larger than two times the propagationtime towards a UE at the cell edge, otherwise, the UL and DL signals inthe cell will interfere. Because of this, the GP is typically chosen todepend on the cell size, such that larger cells (i.e. larger inter-sitedistances) have a larger GP and vice versa.

Additionally, the guard period reduces DL-to-UL interference between BSsby allowing a certain propagation delay between cells without having theDL transmission of a first BS enter the UL reception of a second BS. Ina macro network, the DL transmission power would be on the order of 20dB larger than the UL transmission power, and the pathloss between BSs,perhaps above roof top and in line-of-sight (LOS), may often be muchsmaller than the pathloss between BSs and terminals in non-line-of-sight(NLOS). Hence, if the UL is interfered by the DL of other cells, socalled cross-link interference, the UL performance can be seriouslydegraded. Because of the large transmit power discrepancy between UL andDL and/or propagation conditions, a cross-link interference can bedetrimental to system performance, which is not only for the co-channelcase where DL interferes UL on the same carrier, but also for theadjacent channel case where DL of one carrier interferes with UL on anadjacent carrier. Because of this, the TDD macro networks are typicallyoperated in a synchronized and aligned fashion, where the symbol timingis aligned and a semi-static TDD UL/DL pattern is used. For example, theTDD UL/DL pattern is the same for all the cells in the networks. Byaligning uplink and downlink periods so that they do not occursimultaneously, one proposal is to reduce interference between uplinkand downlink. Typically, operators with adjacent TDD carriers alsosynchronize their TDD UL/DL patterns to avoid adjacent channelcross-link interference.

FIG. 2 illustrates a TDD guard period design. The principle of applyinga GP, at the downlink-to-uplink switch, to avoid DL-to-UL interferencebetween BSs is shown in FIG. 2. The TDD guard period design where avictim BS (V in FIG. 2) is being or at least potentially interfered byan aggressor BS (A in FIG. 2). The aggressor BS sends a DL signal to adevice in its cell, and the DL signal also reaches the victim BS wherethe propagation loss is not enough to protect it from the signals of A.The victim BS is also trying to receive a signal from another terminal(not shown in the figure) in its cell. The signal has propagated adistance d and due to propagation delay, the experienced frame structurealignment of A at V is shifted/delayed τ second, proportional to thepropagation distance d. As illustrated in FIG. 2, although the DL partof the aggressor BS (A) is delayed, it does not enter the UL region ofthe victim BS (V) due to the guard period used. The guard period designfor this TDD system serves the purpose to avoid interference between theBSs. In addition, the aggressor DL signal undergoes attenuation, but maybe very high relative to the received victim UL signal, due todifferences in transmit powers in terminals and base stations as well aspropagation condition differences for base station-to-base station linksand terminal-to-base station links. The terminology of victim andaggressor is only used here to illustrate why typical TDD systems aredesigned as they are. The victim can also act as an aggressor and viceversa and even simultaneously since channel reciprocity exists betweenthe BSs.

For new radio (NR) frame structure in the RAT next generation mobilewireless communication system (i.e., 5G) or NR, the RAT supports adiverse set of use cases and a diverse set of deployment scenarios. Thediverse set of deployment scenarios includes deployment at both lowfrequencies (e.g., 100s of MHz) and very high frequencies (e.g., mmwaves in the tens of GHz).

Similar to LTE, NR uses orthogonal frequency division multiplexing(OFDM) in the downlink from a network node, such as gNB, eNB, or basestation, to a user equipment (UE). The basic NR physical resource overan antenna port can thus be seen as a time-frequency grid as illustratedin FIG. 3, where a resource block (RB) in a 14-symbol slot is shown. Aresource block corresponds to twelve contiguous subcarriers in thefrequency domain. Resource blocks are numbered in the frequency domain,starting with 0 from one end of the system bandwidth. Each resourceelement corresponds to one OFDM subcarrier during one OFDM symbolinterval.

Different subcarrier spacing values are supported in NR. The supportedsubcarrier spacing values (also referred to as different numerologies)are given by Δf=(15×2^(α)) kHz, where α∈(0, 1, 2, 3, 4). Δf being 15 kHzis the basic (or reference) subcarrier spacing that is also used in LTE.

FIG. 3 illustrates an example NR physical resource grid. In the timedomain, downlink and uplink transmissions in NR will be organized intoequally-sized subframes of 1 ms each, similar to LTE. A subframe isfurther divided into multiple slots of equal duration. The slot lengthfor subcarrier spacing Δf=(15×2^(α)) kHz is ½^(α) ms. There is only oneslot per subframe at Δf=15 kHz and a slot consists of 14 OFDM symbols.

Downlink transmissions are dynamically scheduled, i.e., in each slot thegNB transmits downlink control information (DCI) about which UE data isto be transmitted to and which resource blocks in the current downlinkslot the data is transmitted on. This control information is typicallytransmitted in the first one or two OFDM symbols in each slot in NR. Thecontrol information is carried on the Physical Control Channel (PDCCH),and the data is carried on the Physical Downlink Shared Channel (PDSCH).A UE first detects and decodes PDCCH and if a PDCCH is decodedsuccessfully, it then decodes the corresponding PDSCH based on thedecoded control information in the PDCCH.

In addition to PDCCH and PDSCH, there are also other channels andreference signals transmitted in the downlink. Uplink datatransmissions, carried on Physical Uplink Shared Channel (PUSCH), arealso dynamically scheduled by the gNB by transmitting a DCI. In case ofTDD operation, the DCI transmitted in the DL region always indicates ascheduling offset, so that the PUSCH is transmitted in a slot in the ULregion.

Regarding UL-DL configurations in TDD, some subframes/slots areallocated for uplink transmissions, and some subframes/slots areallocated for downlink transmissions. The switch between downlink anduplink occurs in the special subframes (LTE) or flexible slots (NR). InLTE, seven different UL-DL configurations are provided, see Table 1.

TABLE 1 LTE uplink-downlink configurations Downlink-to- Uplink Uplink-Switch- downlink point Subframe number configuration periodicity 0 1 2 34 5 6 7 8 9 0  5 ms D S U U U D S U U U 1  5 ms D S U U D D S U U D 2  5ms D S U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms D S U U D D DD D D 5 10 ms D S U D D D D D D D 6  5 ms D S U U U D S U U D

The size of the guard period can also be configured from a set ofpossible selections. Furthermore, the number of symbols for downlinktransmission in a special subframe (DwPTS) and uplink transmission in aspecial subframe in the special subframe (UpPTS) can also be configured.

NR, on the other hand, provides many different uplink-downlinkconfigurations. There are 10 to 320 slots per radio frame, where eachradio frame has a duration of 10 ms, depending on subcarrier spacing. InTable 2, the OFDM symbols in a slot are classified as ‘downlink’(denoted ‘D’), ‘flexible’ (denoted ‘X’), or ‘uplink’ (denoted ‘U’). Asemi-static TDD UL-DL configuration may be used, where the TDDconfiguration is RRC configured using the IE TDD-UL-DL-ConfigCommon.

TABLE 2 IE of TDD-UL-DL-ConfigCommon TDD-UL-DL-ConfigCommon :: = SEQUENCE {  -- Reference SCS used to determine the time domainboundaries in the UL-DL pattern which must be common across allsubcarrier specific  -- virtual carriers, i.e., independent of theactual subcarrier spacing using for data transmission.  -- Only thevalues 15 or 30 kHz (<6GHz), 60 or 120 kHz (>6GHz) are applicable.  --Corresponds to L1 parameter ‘reference-SCS’ (see 38.211, sectionFFS_Section)  referenceSubcarrierSpacing     SubcarrierSpacing          OPTIONAL,  -- Periodicity of the DL-UL pattern. Corresponds toL1 parameter ‘DL-UL- transmission-periodicity’ (see 38.211, sectionFFS_Section)  d1-UL-TransmissionPeriodicity  ENUMERATED {ms0p5, ms0p625,ms1, ms1p25, ms2, ms2p5, ms5, ms10}      OPTIONAL,  -- Number ofconsecutive full DL slots at the beginning of each DL-UL pattern.  --Corresponds to L1 parameter ‘number-of-DL-slots’ (see 38.211, Table4.3.2-1)  nrofDownlinkSlots      INTEGER (0..maxNrofSlots)              OPTIONAL,  -- Number of consecutive DL symbols in thebeginning of the slot following the last full DL slot (as derived fromnrofDownlinkSlots).  -- If the field is absent or released, there is nopartial-downlink slot.  -- Corresponds to L1 parameter‘number-of-DL-symbols-common’ (see 38.211, section FFS_Section). nrofDownlinkSymbols      INTEGER (0..maxNrofSymbols-1)              OPTIONAL, -- Need R  -- Number of consecutive full ULslots at the end of each DL-UL pattern.  -- Corresponds to L1 parameter‘number-of-UL-slots’ (see 38.211, Table 4.3.2-1) nrofUplinkSlots         INTEGER (0..maxNrofSlots)                 OPTIONAL,  -- Numberof consecutive UL symbols in the end of the slot preceding the firstfull UL slot (as derived from nrofUplinkSlots).  -- If the field isabsent or released, there is no partial-uplink slot.  -- Corresponds toL1 parameter ‘number-of-UL-symbols-common’ (see 38.211, sectionFFS_Section)  nrofUplinkSymbols     INTEGER (0..maxNrofSymbols-1)           OPTIONAL -- Need R

Or alternatively, the slot format can be dynamically indicated with aSlot Format Indicator (SFI) conveyed with DCI Format 2_0. Regardless, ifdynamic or semi-static TDD configuration is used in NR, the number of ULand DL slots, as well as the guard period may be almost arbitrarilyconfigured within the TDD periodicity. In addition, because of the guardperiod being configured, the number of UL and DL symbols in the flexibleslot(s) is also configured. This allows for flexible uplink-downlinkconfigurations.

For an atmospheric ducting used in certain weather conditions and incertain regions of the world, a ducting phenomenon can happen in theatmosphere. The appearance of the duct is dependent on, for example,temperature and humidity, and when the atmospheric ducting appears, itcan “channel” the signal to help it propagate a significantly longerdistance than if the duct was not present. An atmospheric duct is alayer in which rapid decrease in the refractivity of the loweratmosphere, e.g., the troposphere, occurs. In this way, atmosphericducts can trap the propagating signals in the ducting layer, instead ofradiating out in space. Thus, most of the signal energy propagates inducting layer which acts as a wave guide. Therefore, trapped signals canpropagate through beyond-line-of-sight distances with relatively lowpath loss, sometimes even lower than in LOS propagation. A ducting eventis typically temporary and can have a time duration from a couple ofminutes to several hours. When the ducting event occurs, a BS can beinterfered by thousands of BS, and a single BS can interfere thousandsof BSs. Potential coordination between the aggressor BS and a largenumber of victim BSs would incur a significant backhaul signaling loadand would not scale.

There currently exist certain challenges. The existing challenges arehow to enable coordination, over backhaul, between an aggressor BS and alarge number of victim BSs in a remote interference scenario, withoutincurring a large signaling load on the backhaul. A new design tocoordinate the interference between the aggressor BSs and the victim BSsis required.

SUMMARY

To address the foregoing problems with existing solutions, disclosed area method and a network node, to enable remote interference management(RIM) coordination information exchange between an aggressor basestation and a group of victim base stations over backhaul. The presentdisclosure implements a solution to solve a remote interference occurredin the current time division duplex (TDD) system and a presence of anatmospheric duct by allowing a network node to act as a central unit tohandle RIM-related messages for a group of network nodes. Furthermore,by signaling the RIM-related messages only between the central units,the method and the network node disclosed herein may avoid a largesignaling load on the backhaul, and therefore, can be scalable in thesystem and improves the preference of the network.

Several embodiments are elaborated in this disclosure. According to oneembodiment of a method for interference coordination, the methodcomprises receiving, from a first network node, a reference signalindicating that one or more second network nodes are experiencinginterference. The reference signal indicates at least one identifier forthe first network node and the one or more second network nodes. Themethod further comprises preparing a remote interference management(RIM) coordination message based on the reference signal. The methodadditionally comprises sending, to the first network node, the RIMcoordination message to be forwarded to the one or more second networknodes.

In one embodiment, the first network node is a central unit and the oneor more second network nodes are a group of distributed units.

In one embodiment, the first network node is an Access and MobilityManagement Function (AMF) node.

In one embodiment, the sending step comprises establishing a connectionwith the first network node, sending the RIM coordination message to thefirst network node over backhaul; and forwarding the RIM coordinationmessage to the one or more second network nodes via a Xn interface. In aparticular embodiment, the connection is a route via an intermediatenetwork node in a core network.

In one embodiment, the preparing step comprises transmitting, to a thirdnetwork node, the RIM coordination message over backhaul, aggregating,at the third network node, the RIM coordination message transmitted overbackhaul, and identifying, at the third network node, a first identifierfor the first network node and a second identifier for the one or moresecond network nodes based on the reference signal. In one embodiment,the first identifier and the second identifier may be included in theRIM coordination message aggregated at the third network node.

In one embodiment, the identifying step comprises retrieving, at thethird network node, mapping information from a database in a corenetwork, wherein the mapping information comprises a mapping between thefirst identifier and the second identifier. In a particular embodiment,the third network node is an AMF node.

In one embodiment, the first identifier for the first network node is anAMF ID, an AMF set ID, an AMF region ID, or a preconfigured index whichindicates the first network node.

In one embodiment, the second identifier for the one or more secondnetwork nodes is a reference signal group (RSG) ID which identifies anindividual network node or a group of network nodes associated with thefirst network node associated with the first identifier.

According to an embodiment of a network node for interferencecoordination, the network node comprises at least one processingcircuitry, and at least one storage that stores processor-executableinstructions, when executed by the processing circuitry, causes anetwork node to receive, from a first network node, a reference signalindicating that one or more second network nodes are experiencinginterference. The reference signal indicates at least one identifier forthe first network node and for the one or more second network nodes. Thenetwork node further prepares a remote interference management (RIM)coordination message based on the reference signal. The network nodeadditionally sends, to the first network node, the RIM coordinationmessage to be forwarded to the one or more second network nodes.

Certain aspects of the present disclosure and their embodiments mayprovide solutions to these or other challenges. There are, proposedherein, various embodiments which address one or more of the issuesdisclosed herein.

Certain embodiments may provide one or more of the following technicaladvantages. The methods disclosed in the present disclosure may providean efficient and scalable solution for communication system to allowRIM-related messages exchange between an aggressor master network nodeand a victim master network node, such that the aggressor master networknode avoids a direct communication to all victim network nodes.Therefore, particular embodiments may be scalable in the system andreduce a large signaling in the network efficiently, and further improvethe performance of the network.

Various other features and advantages will become obvious to one ofordinary skill in the art in light of the following detailed descriptionand drawings. Certain embodiments may have none, some, or all of therecited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIG. 1 illustrates a block diagram of an example 5G system architecture;

FIG. 2 illustrates a diagram of a time division duplex (TDD) guarddesign in 5G system architecture;

FIG. 3 illustrates a diagram of an example NR physical resource grid;

FIG. 4 illustrates an example wireless network, according to certainembodiments;

FIG. 5 illustrates an example user equipment, according to certainembodiments;

FIG. 6 illustrates an example virtualization environment, according tocertain embodiments;

FIG. 7 illustrates a diagram of an example TDD guard period design in 5Gsystem architecture, according to certain embodiments;

FIG. 8 illustrates a block diagram of an example method for coordinatinginterference with a master network node, according to certainembodiments;

FIG. 9 illustrates a block diagram of an example method for signalingbetween aggressor BSs and victim BSs, according to certain embodiments;

FIG. 10 illustrates a block diagram of an example method for signalingbetween two master network nodes, according to certain embodiments;

FIG. 11 illustrates an example telecommunication network connected viaan intermediate network to a host computer, according to certainembodiments;

FIG. 12 illustrates an example host computer communicating via a basestation with a user equipment over a partially wireless connection,according to certain embodiments;

FIG. 13 illustrates an example method implemented in a communicationsystem including a host computer, a base station and a user equipment,according to certain embodiments;

FIG. 14 illustrates another example method implemented in acommunication system including a host computer, a base station and auser equipment, according to certain embodiments;

FIG. 15 illustrates another further example method implemented in acommunication system including a host computer, a base station and auser equipment, according to certain embodiments;

FIG. 16 illustrates another yet example method implemented in acommunication system including a host computer, a base station and auser equipment, according to certain embodiments;

FIG. 17 illustrates a flow diagram of an example method performed at anetwork node, in accordance with certain embodiments; and

FIG. 18 illustrates a block schematic of an example network node, inaccordance with certain embodiments.

DETAILED DESCRIPTION

Current guard period design for Time Division Duplex (TDD) in 5Gcommunication network causes interferences and delays in signalingbetween base stations. Furthermore, a presence of atmospheric ductingalso causes downlink interferences to a victim base station by anaggressor base station in the distance. Therefore, the interferences canbe extensive. However, existing methods to such interferences incur alarge signaling load on the backhaul and cannot be scalable. Particularembodiments of the present disclosure provide a central network node tocoordinate remote interferences for a group of network nodes whichassociate with the central network node. Therefore, particularembodiments of the present disclosure may avoid a large amount of directcommunications with each victim network node, which reduces a waste onthe resource in the network.

Furthermore, both of the victim network nodes and the aggressor networknodes may have their own central network nodes respectively, e.g., acentral victim network node and a central aggressor network node, suchthat a remote interference management (RIM) coordination message can beexchanged between the central victim network node and the centralaggressor network node via the backhaul, and the RIM coordinationmessage would then be forwarded to their respective groups of networknodes. Therefore, particular embodiments of the present disclosure maybe scalable for a broad range of interference, and furthermore, improvethe performance of the network.

In particular embodiments of the present disclosure, the central victimnetwork node and the central aggressor network node may be a gNB centralunit (CU). The gNB CU collects and merges each RIM coordinationinformation sent from a group of distributed units (DUs) that the gNB CUis in charge of, and then forwards a merged RIM coordination message toanother gNB CU. For example, an aggressor gNB CU exchanges a merged RIMcoordination message, which is merged based on RIM coordinationinformation received from the DUs, with a victim gNB CU. Furthermore,the victim gNB CU may distribute the merged RIM coordination message torelevant gNB DUs, such as the gNB DU identified in the merged RIMcoordination message.

In the present disclosure, a network node may be referred to as a basestation. The base station is a general term and can correspond to anytype of radio network node or any network node, which communicates witha UE and/or with another network node. Examples of network nodes areNodeB, base station (BS), multi-standard radio (MSR) radio node, such asMSR BS, eNB, gNB. MeNB, SeNB, network controller, radio networkcontroller (RNC), core network node (AMF, MME, MSC etc.), base stationcontroller (BSC), road side unit (RSU), relay, donor node controllingrelay, base transceiver station (BTS), access point (AP), transmissionpoints, transmission nodes, RRU, RRH, nodes in distributed antennasystem (DAS), O&M, OSS, SON, positioning node (e.g. E-SMLC) etc.

The term radio access technology, or RAT, may refer to any RAT e.g.UTRA, E-UTRA, narrow band internet of things (NB-IoT), WiFi, Bluetooth,next generation RAT (NR), 4G, 5G, etc. Any of the first and the secondnodes may be capable of supporting a single or multiple RATs.

The term reference signal used herein can be any physical signal orphysical channel Examples of downlink reference signals are PSS, SSS,CRS, PRS, CSI-RS, DMRS, NRS, NPSS, NSSS, SS, MBSFN RS etc. Examples ofuplink reference signals are SRS, DMRS etc.

FIG. 4 is an example wireless network, in accordance with certainembodiments. Although the subject matter described herein may beimplemented in any appropriate type of system using any suitablecomponents, the embodiments disclosed herein are described in relationto a wireless network, such as the example wireless network illustratedin FIG. 4. For simplicity, the wireless network of FIG. 4 only depictsnetwork 406, network nodes 460 and 460 b, and wireless devices (WDs)410, 410 b, and 410 c. In practice, a wireless network may furtherinclude any additional elements suitable to support communicationbetween wireless devices or between a wireless device and anothercommunication device, such as a landline telephone, a service provider,or any other network node or end device. Of the illustrated components,network node 460 and wireless device (WD) 410 are depicted withadditional detail. In some embodiments, the network node 460 may be abase station, such as an eNB. In the present disclosure, the term eNBmay be used to refer to both an eNB and a ng-eNB unless there is aspecific need to distinguish between the two. In certain embodiments,the network node 460 may be a network node, which is further illustratedin FIG. 18. In certain embodiments, the network node 460 may be a sourcenetwork node. In certain embodiments, the network node 460 may be atarget network node. The wireless network may provide communication andother types of services to one or more wireless devices to facilitatethe wireless devices' access to and/or use of the services provided by,or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless localarea network (WLAN) standards, such as the IEEE 802.11 standards; and/orany other appropriate wireless communication standard, such as theWorldwide Interoperability for Microwave Access (WiMax), Bluetooth,Z-Wave and/or ZigBee standards.

Network 406 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 460 and WD 410 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 4, network node 460 includes processing circuitry 470, devicereadable medium 480, interface 490, auxiliary equipment 488, powersource 486, power circuitry 487, and antenna 462. Although network node460 illustrated in the example wireless network of FIG. 4 may representa device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 460 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 480 may comprise multiple separate hard drives aswell as multiple RAM modules).

Similarly, network node 460 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 460comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeBs. Insuch a scenario, each unique NodeB and RNC pair, may in some instancesbe considered a single separate network node. In some embodiments,network node 460 may be configured to support multiple radio accesstechnologies (RATs). In such embodiments, some components may beduplicated (e.g., separate device readable medium 480 for the differentRATs) and some components may be reused (e.g., the same antenna 462 maybe shared by the RATs). Network node 460 may also include multiple setsof the various illustrated components for different wirelesstechnologies integrated into network node 460, such as, for example,GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. Thesewireless technologies may be integrated into the same or different chipor set of chips and other components within network node 460.

Processing circuitry 470 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 470 may include processing informationobtained by processing circuitry 470 by, for example, converting theobtained information into other information, comparing the obtainedinformation or converted information to information stored in thenetwork node, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Processing circuitry 470 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 460 components, such as device readable medium 480, network node460 functionality. For example, processing circuitry 470 may executeinstructions stored in device readable medium 480 or in memory withinprocessing circuitry 470. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 470 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 470 may include one or more ofradio frequency (RF) transceiver circuitry 472 and baseband processingcircuitry 474. In some embodiments, radio frequency (RF) transceivercircuitry 472 and baseband processing circuitry 474 may be on separatechips (or sets of chips), boards, or units, such as radio units anddigital units. In alternative embodiments, part or all of RF transceivercircuitry 472 and baseband processing circuitry 474 may be on the samechip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 470executing instructions stored on device readable medium 480 or memorywithin processing circuitry 470. In alternative embodiments, some or allof the functionality may be provided by processing circuitry 470 withoutexecuting instructions stored on a separate or discrete device readablemedium, such as in a hard-wired manner. In any of those embodiments,whether executing instructions stored on a device readable storagemedium or not, processing circuitry 470 can be configured to perform thedescribed functionality. In particular embodiments, the processingcircuitry 470 of the network node 460 may perform a method which isfurther illustrated in FIG. 17. The benefits provided by suchfunctionality are not limited to processing circuitry 470 alone or toother components of network node 460 but are enjoyed by network node 460as a whole, and/or by end users and the wireless network generally.

Device readable medium 480 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 470. Device readable medium 480 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 470 and, utilized by network node 460. Devicereadable medium 480 may be used to store any calculations made byprocessing circuitry 470 and/or any data received via interface 490. Insome embodiments, processing circuitry 470 and device readable medium480 may be considered to be integrated.

Interface 490 is used in the wired or wireless communication ofsignaling and/or data between network node 460, network 406, and/or WDs410. As illustrated, interface 490 comprises port(s)/terminal(s) 494 tosend and receive data, for example to and from network 406 over a wiredconnection. Interface 490 also includes radio front end circuitry 492that may be coupled to, or in certain embodiments a part of, antenna462. Radio front end circuitry 492 comprises filters 498 and amplifiers496. Radio front end circuitry 492 may be connected to antenna 462 andprocessing circuitry 470. Radio front end circuitry may be configured tocondition signals communicated between antenna 462 and processingcircuitry 470. Radio front end circuitry 492 may receive digital datathat is to be sent out to other network nodes or WDs via a wirelessconnection. Radio front end circuitry 492 may convert the digital datainto a radio signal having the appropriate channel and bandwidthparameters using a combination of filters 498 and/or amplifiers 496. Theradio signal may then be transmitted via antenna 462. Similarly, whenreceiving data, antenna 462 may collect radio signals which are thenconverted into digital data by radio front end circuitry 492. Thedigital data may be passed to processing circuitry 470. In otherembodiments, the interface may comprise different components and/ordifferent combinations of components.

In certain alternative embodiments, network node 460 may not includeseparate radio front end circuitry 492, instead, processing circuitry470 may comprise radio front end circuitry and may be connected toantenna 462 without separate radio front end circuitry 492. Similarly,in some embodiments, all or some of RF transceiver circuitry 472 may beconsidered a part of interface 490. In still other embodiments,interface 490 may include one or more ports or terminals 494, radiofront end circuitry 492, and RF transceiver circuitry 472, as part of aradio unit (not shown), and interface 490 may communicate with basebandprocessing circuitry 474, which is part of a digital unit (not shown).

Antenna 462 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 462 may becoupled to radio front end circuitry 490 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 462 may comprise one or more omni-directional,sector or panel antennas operable to transmit/receive radio signalsbetween, for example, 2 GHz and 66 GHz. An omni-directional antenna maybe used to transmit/receive radio signals in any direction, a sectorantenna may be used to transmit/receive radio signals from deviceswithin a particular area, and a panel antenna may be a line of sightantenna used to transmit/receive radio signals in a relatively straightline. In some instances, the use of more than one antenna may bereferred to as MIMO. In certain embodiments, antenna 462 may be separatefrom network node 460 and may be connectable to network node 460 throughan interface or port.

Antenna 462, interface 490, and/or processing circuitry 470 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 462, interface 490, and/or processing circuitry 470 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 487 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node 460with power for performing the functionality described herein. Powercircuitry 487 may receive power from power source 486. Power source 486and/or power circuitry 487 may be configured to provide power to thevarious components of network node 460 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 486 may either be included in,or external to, power circuitry 487 and/or network node 460. Forexample, network node 460 may be connectable to an external power source(e.g., an electricity outlet) via an input circuitry or interface suchas an electrical cable, whereby the external power source supplies powerto power circuitry 487. As a further example, power source 486 maycomprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 487. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 460 may include additionalcomponents beyond those shown in FIG. 4 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 460 may include user interface equipment to allow input ofinformation into network node 460 and to allow output of informationfrom network node 460. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node460.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE). a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a WD mayrepresent a machine or other device that performs monitoring and/ormeasurements, and transmits the results of such monitoring and/ormeasurements to another WD and/or a network node. The WD may in thiscase be a machine-to-machine (M2M) device, which may in a 3GPP contextbe referred to as an MTC device. As one particular example, the WD maybe a UE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g. refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 410 includes antenna 411, interface 414,processing circuitry 420, device readable medium 430, user interfaceequipment 432, auxiliary equipment 434, power source 436 and powercircuitry 437. WD 410 may include multiple sets of one or more of theillustrated components for different wireless technologies supported byWD 410, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, orBluetooth wireless technologies, just to mention a few. These wirelesstechnologies may be integrated into the same or different chips or setof chips as other components within WD 410.

Antenna 411 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 414. In certain alternative embodiments, antenna 411 may beseparate from WD 410 and be connectable to WD 410 through an interfaceor port. Antenna 411, interface 414, and/or processing circuitry 420 maybe configured to perform any receiving or transmitting operationsdescribed herein as being performed by a WD. Any information, dataand/or signals may be received from a network node and/or another WD. Insome embodiments, radio front end circuitry and/or antenna 411 may beconsidered an interface.

As illustrated, interface 414 comprises radio front end circuitry 412and antenna 411. Radio front end circuitry 412 comprise one or morefilters 418 and amplifiers 416. Radio front end circuitry 414 isconnected to antenna 411 and processing circuitry 420, and is configuredto condition signals communicated between antenna 411 and processingcircuitry 420. Radio front end circuitry 412 may be coupled to or a partof antenna 411. In some embodiments, WD 410 may not include separateradio front end circuitry 412; rather, processing circuitry 420 maycomprise radio front end circuitry and may be connected to antenna 411.Similarly, in some embodiments, some or all of RF transceiver circuitry422 may be considered a part of interface 414. Radio front end circuitry412 may receive digital data that is to be sent out to other networknodes or WDs via a wireless connection. Radio front end circuitry 412may convert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 418and/or amplifiers 416. The radio signal may then be transmitted viaantenna 411. Similarly, when receiving data, antenna 411 may collectradio signals which are then converted into digital data by radio frontend circuitry 412. The digital data may be passed to processingcircuitry 420. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

Processing circuitry 420 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 410components, such as device readable medium 430, WD 410 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry420 may execute instructions stored in device readable medium 430 or inmemory within processing circuitry 420 to provide the functionalitydisclosed herein. In particular embodiments, the processing circuitry420 of the WD 410 may execute instructions to perform measurements forcertain cells in the network 406, which is further illustrated below.

As illustrated, processing circuitry 420 includes one or more of RFtransceiver circuitry 422, baseband processing circuitry 424, andapplication processing circuitry 426. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry420 of WD 410 may comprise a SOC. In some embodiments, RF transceivercircuitry 422, baseband processing circuitry 424, and applicationprocessing circuitry 426 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry424 and application processing circuitry 426 may be combined into onechip or set of chips, and RF transceiver circuitry 422 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 422 and baseband processing circuitry424 may be on the same chip or set of chips, and application processingcircuitry 426 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 422,baseband processing circuitry 424, and application processing circuitry426 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 422 may be a part of interface414. RF transceiver circuitry 422 may condition RF signals forprocessing circuitry 420.

In certain embodiments, some or all of the functionalities describedherein as being performed by a WD may be provided by processingcircuitry 420 executing instructions stored on device readable medium430, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 420 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner. In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 420 can be configured to perform the describedfunctionality. The benefits provided by such functionality are notlimited to processing circuitry 420 alone or to other components of WD410, but are enjoyed by WD 410 as a whole, and/or by end users and thewireless network generally.

Processing circuitry 420 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 420, may include processinginformation obtained by processing circuitry 420 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 410, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 430 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 420. Device readable medium 430 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 420. In someembodiments, processing circuitry 420 and device readable medium 430 maybe considered to be integrated.

User interface equipment 432 may provide components that allow for ahuman user to interact with WD 410. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment432 may be operable to produce output to the user and to allow the userto provide input to WD 410. The type of interaction may vary dependingon the type of user interface equipment 432 installed in WD 410. Forexample, if WD 410 is a smart phone, the interaction may be via a touchscreen; if WD 410 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 432 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 432 is configured to allow input of information into WD 410,and is connected to processing circuitry 420 to allow processingcircuitry 420 to process the input information. User interface equipment432 may include, for example, a microphone, a proximity or other sensor,keys/buttons, a touch display, one or more cameras, a USB port, or otherinput circuitry. User interface equipment 432 is also configured toallow output of information from WD 410, and to allow processingcircuitry 420 to output information from WD 410. User interfaceequipment 432 may include, for example, a speaker, a display, vibratingcircuitry, a USB port, a headphone interface, or other output circuitry.Using one or more input and output interfaces, devices, and circuits, ofuser interface equipment 432, WD 410 may communicate with end usersand/or the wireless network, and allow them to benefit from thefunctionality described herein.

Auxiliary equipment 434 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 434 may vary depending on the embodiment and/or scenario.

Power source 436 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 410 may further comprise power circuitry 437for delivering power from power source 436 to the various parts of WD410 which need power from power source 436 to carry out anyfunctionality described or indicated herein. Power circuitry 437 may incertain embodiments comprise power management circuitry. Power circuitry437 may additionally or alternatively be operable to receive power froman external power source; in which case WD 410 may be connectable to theexternal power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 437 may also in certain embodiments be operable to deliverpower from an external power source to power source 436. This may be,for example, for the charging of power source 436. Power circuitry 437may perform any formatting, converting, or other modification to thepower from power source 436 to make the power suitable for therespective components of WD 410 to which power is supplied.

FIG. 5 illustrates one embodiment of a UE, in accordance with certainembodiments. As used herein, a user equipment or UE may not necessarilyhave a user in the sense of a human user who owns and/or operates therelevant device. Instead, a UE may represent a device that is intendedfor sale to, or operation by, a human user but which may not, or whichmay not initially, be associated with a specific human user (e.g., asmart sprinkler controller). Alternatively, a UE may represent a devicethat is not intended for sale to, or operation by, an end user but whichmay be associated with or operated for the benefit of a user (e.g., asmart power meter). UE 400 may be any UE identified by the 3rdGeneration Partnership Project (3GPP), including a NB-IoT UE, a MTC UE,and/or an enhanced MTC (eMTC) UE. UE 500, as illustrated in FIG. 5, isone example of a WD configured for communication in accordance with oneor more communication standards promulgated by the 3rd GenerationPartnership Project (3GPP), such as 3GPP's GSM, UMTS, LTE, and/or 5Gstandards. As mentioned previously, the term WD and UE may be usedinterchangeable. Accordingly, although FIG. 5 is a UE, the componentsdiscussed herein are equally applicable to a WD, and vice-versa.

In FIG. 5, UE 500 includes processing circuitry 501 that is operativelycoupled to input/output interface 505, radio frequency (RF) interface509, network connection interface 511, memory 515 including randomaccess memory (RAM) 517, read-only memory (ROM) 519, and storage medium521 or the like, communication subsystem 531, power source 533, and/orany other component, or any combination thereof. Storage medium 521includes operating system 523, application program 525, and data 527. Inother embodiments, storage medium 521 may include other similar types ofinformation. Certain UEs may utilize all of the components shown in FIG.5, or only a subset of the components. The level of integration betweenthe components may vary from one UE to another UE. Further, certain UEsmay contain multiple instances of a component, such as multipleprocessors, memories, transceivers, transmitters, receivers, etc.

In FIG. 5, processing circuitry 501 may be configured to processcomputer instructions and data. Processing circuitry 501 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 501 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer. In certain embodiment, processingcircuitry 501 may perform a method which is further illustrated in FIG.17.

In the depicted embodiment, input/output interface 505 may be configuredto provide a communication interface to an input device, output device,or input and output device. UE 500 may be configured to use an outputdevice via input/output interface 505. An output device may use the sametype of interface port as an input device. For example, a USB port maybe used to provide input to and output from UE 500. The output devicemay be a speaker, a sound card, a video card, a display, a monitor, aprinter, an actuator, an emitter, a smartcard, another output device, orany combination thereof. UE 500 may be configured to use an input devicevia input/output interface 505 to allow a user to capture informationinto UE 500. The input device may include a touch-sensitive orpresence-sensitive display, a camera (e.g., a digital camera, a digitalvideo camera, a web camera, etc.), a microphone, a sensor, a mouse, atrackball, a directional pad, a trackpad, a scroll wheel, a smartcard,and the like. The presence-sensitive display may include a capacitive orresistive touch sensor to sense input from a user. A sensor may be, forinstance, an accelerometer, a gyroscope, a tilt sensor, a force sensor,a magnetometer, an optical sensor, a proximity sensor, another likesensor, or any combination thereof. For example, the input device may bean accelerometer, a magnetometer, a digital camera, a microphone, and anoptical sensor.

In FIG. 5, RF interface 509 may be configured to provide a communicationinterface to RF components such as a transmitter, a receiver, and anantenna. Network connection interface 511 may be configured to provide acommunication interface to network 543 a. Network 543 a may encompasswired and/or wireless networks such as a local-area network (LAN), awide-area network (WAN), a computer network, a wireless network, atelecommunications network, another like network or any combinationthereof. For example, network 543 a may comprise a Wi-Fi network.Network connection interface 511 may be configured to include a receiverand a transmitter interface used to communicate with one or more otherdevices over a communication network according to one or morecommunication protocols, such as Ethernet, TCP/IP, SONET, ATM, or thelike. Network connection interface 511 may implement receiver andtransmitter functionality appropriate to the communication network links(e.g., optical, electrical, and the like). The transmitter and receiverfunctions may share circuit components, software or firmware, oralternatively may be implemented separately.

RAM 517 may be configured to interface via bus 502 to processingcircuitry 501 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 519 maybe configured to provide computer instructions or data to processingcircuitry 501. For example, ROM 519 may be configured to store invariantlow-level system code or data for basic system functions such as basicinput and output (I/O), startup, or reception of keystrokes from akeyboard that are stored in a non-volatile memory. Storage medium 521may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 521 may be configured toinclude operating system 523, application program 525 such as a webbrowser application, a widget or gadget engine or another application,and data file 527. Storage medium 521 may store, for use by UE 500, anyof a variety of various operating systems or combinations of operatingsystems.

Storage medium 521 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 521 may allow UE 500 to access computer-executable instructions,application programs or the like, stored on transitory or non-transitorymemory media, to off-load data, or to upload data. An article ofmanufacture, such as one utilizing a communication system may betangibly embodied in storage medium 521, which may comprise a devicereadable medium.

In FIG. 5, processing circuitry 501 may be configured to communicatewith network 543 b using communication subsystem 531. Network 543 a andnetwork 543 b may be the same network or networks or different networkor networks. Communication subsystem 531 may be configured to includeone or more transceivers used to communicate with network 543 b. Forexample, communication subsystem 531 may be configured to include one ormore transceivers used to communicate with one or more remotetransceivers of another device capable of wireless communication such asanother WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.5,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 533 and/or receiver 535 to implement transmitter orreceiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 533 andreceiver 535 of each transceiver may share circuit components, softwareor firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 531 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 531 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 543 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network543 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 513 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 500.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 500 or partitioned acrossmultiple components of UE 500. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem531 may be configured to include any of the components described herein.Further, processing circuitry 501 may be configured to communicate withany of such components over bus 502. In another example, any of suchcomponents may be represented by program instructions stored in memorythat when executed by processing circuitry 501 perform the correspondingfunctions described herein. In another example, the functionality of anyof such components may be partitioned between processing circuitry 501and communication subsystem 531. In another example, thenon-computationally intensive functions of any of such components may beimplemented in software or firmware and the computationally intensivefunctions may be implemented in hardware.

FIG. 6 illustrates an example virtualization environment, in accordancewith certain embodiments. FIG. 6 is a schematic block diagramillustrating a virtualization environment 600 in which functionsimplemented by some embodiments may be virtualized. In the presentcontext, virtualizing means creating virtual versions of apparatuses ordevices which may include virtualizing hardware platforms, storagedevices and networking resources. As used herein, virtualization can beapplied to a node (e.g., a virtualized base station or a virtualizedradio access node) or to a device (e.g., a UE, a wireless device or anyother type of communication device) or components thereof and relates toan implementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 600 hosted byone or more of hardware nodes 630. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 620 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 620 are run invirtualization environment 600 which provides hardware 630 comprisingprocessing circuitry 660 and memory 690. Memory 690 containsinstructions 695 executable by processing circuitry 660 wherebyapplication 620 is operative to provide one or more of the features,benefits, and/or functions disclosed herein.

Virtualization environment 600, comprises general-purpose orspecial-purpose network hardware devices 630 comprising a set of one ormore processors or processing circuitry 660, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 690-1 which may benon-persistent memory for temporarily storing instructions 695 orsoftware executed by processing circuitry 660. Each hardware device maycomprise one or more network interface controllers (NICs) 670, alsoknown as network interface cards, which include physical networkinterface 680. Each hardware device may also include non-transitory,persistent, machine-readable storage media 690-2 having stored thereinsoftware 695 and/or instructions executable by processing circuitry 660.Software 695 may include any type of software including software forinstantiating one or more virtualization layers 650 (also referred to ashypervisors), software to execute virtual machines 640 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 640, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 650 or hypervisor. Differentembodiments of the instance of virtual appliance 620 may be implementedon one or more of virtual machines 640, and the implementations may bemade in different ways.

During operation, processing circuitry 660 executes software 695 toinstantiate the hypervisor or virtualization layer 650, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 650 may present a virtual operating platform thatappears like networking hardware to virtual machine 640.

As shown in FIG. 6, hardware 630 may be a standalone network node withgeneric or specific components. Hardware 630 may comprise antenna 6225and may implement some functions via virtualization. Alternatively,hardware 630 may be part of a larger cluster of hardware (e.g. such asin a data center or customer premise equipment (CPE)) where manyhardware nodes work together and are managed via management andorchestration (MANO) 6100, which, among others, oversees lifecyclemanagement of applications 620.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high-volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 640 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 640, and that part of hardware 630 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 640, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 640 on top of hardware networking infrastructure630 and corresponds to application 620 in FIG. 6.

In some embodiments, one or more radio units 6200 that each include oneor more transmitters 6220 and one or more receivers 6210 may be coupledto one or more antennas 6225. Radio units 6200 may communicate directlywith hardware nodes 630 via one or more appropriate network interfacesand may be used in combination with the virtual components to provide avirtual node with radio capabilities, such as a radio access node or abase station.

In some embodiments, some signaling can be affected with the use ofcontrol system 6230 which may alternatively be used for communicationbetween the hardware nodes 630 and radio units 6200.

FIG. 7 illustrates an example DL interference from an aggressor BS intoan UL region of a victim BS with a presence of an atmospheric duct, inaccordance with certain embodiments. Due to the inherent properties ofthe TDD system design and the presence of the atmospheric duct, thedistance d between the aggressor BS A that interferes with the victim BSV can be large. Ducting has typically been considered in design ofcellular systems using paired spectrum. Consequently, a DL transmissionwould suddenly enter the UL region as interference I, as illustrated inFIG. 7.

For detecting interference between BSs, the victim BS, i.e. a BS thathas detected it is being interfered due to the atmospheric ducting,sends a specific reference signal (RS) that can be detected by theaggressor BS. The aggressor BS can then adapt its transmission to avoidthe interference situation. Such adaptation is to, for example, blank,or reduce the duration of its downlink transmission, effectivelyincreasing the guard period.

In some embodiments, the aggressor BS uses backhaul signaling to informthe victim BS(s) that it has received the RS. In some embodiments, thevictim BS(s) transmit, via backhaul, some assistance information to theaggressor BS. In some embodiments, the aggressor BS explicitly informsthe victim BS(s), via backhaul, that the RS from the victim BS(s) is nolonger being received.

In some embodiments, a central network node enables an exchange of RIMcoordination information over the backhaul for a large number of victimBSs in a remote interference scenario.

To mitigate the remote interference, i.e., DL-to-UL interference,occurring due to the ducting events in TDD macro deployments, remoteinterference management is utilized. For instance, the aggressor BS mayincrease its GP, and thereby reduce the number of DL symbols in itscell. While this reduces DL capacity in the aggressor cell, it mayreduce the UL interference level in the victim cell and therefore bebeneficial to the overall network performance. As such a measurementmutes resources in one cell to protect resources in another cell, it iscrucial to only apply the mechanism when the remote BS aggressor isactually causing interference to the victim, i.e. when a troposphericducting event occurs. Thus, the potential aggressor BS needs to be madeaware of that it is causing interference to a potential victim BS inorder to know when to apply the remote interference mitigationmechanism.

In some embodiments for remote interference mitigation, the victim BS ofremote interference transmits a RS in certain time locations in order tomake aggressor BS(s) aware that they are causing interference to thevictim BS. Since the propagation channel is reciprocal in TDD systems,the aggressor BS would receive the RS at the same signal strength as thevictim BS receives the aggressor BS's interfering signal, given that thesame Tx power and Tx/Rx antenna patterns are used for bothtransmissions. A potential aggressor BS would then monitor certain timelocations for the RSs transmitted by potential victim BSs, and upondetection of an RS sequence, it would infer that it is causing remoteinterference to a certain victim BSs, whereon it may apply a remoteinterference mitigation mechanism. Such an RS is typically transmittedby the victim BS at the end of the DL region which is right before theGP, and the potential aggressor BS monitors the start of the UL regionwhich is right after the GP for the transmitted RSs.

In some embodiments from the aspect of an aggressor BS, the aggressor BSreceives a RS. Based on the information received in the RS, theaggressor BS first learns that it is causing interference to a group ofvictim BSs, belonging to the same reference signal group (RSG). The RSGmay comprise one or more victim BSs. In some embodiments, the RS mayalso convey information about the identifier of the core network node incharge of mobility management (e.g., MM node) of the victim BS(s). Theaggressor BS's MM node establishes a connection to the victim BSs' MMnode, which, in turn distributes the RIM coordination message to itsaffiliated BSs that are victimized by the aggressor BS. In someembodiments, a management node of the aggressor BS may not be in thecore network. In some embodiments, the management node of theaggressor/victim BS may be a central unit, and the otheraggressor/victim BSs may be distributed units associated with thecentral unit.

In some embodiments from the aspect of a victim BS, the MM nodeaffiliated to the victim RSG aggregates RIM coordination informationreceived from each individual victim BS, and then sends the aggregateRIM coordination information to the aggressor BS. In particularembodiments, one BS among the victim BSs may act as a “master BS” whichreceives the RIM coordination message from the core network, distributesthe information to the other BSs under its supervision, collects andaggregates the RIM coordination information in response, and thentransmits back the aggregated response to the core network when needed.This master BS may also control how the other BSs are sending the RS. Insome embodiments, the master BS may be a master victim BS and/or amaster aggressor BS, as shown in FIG. 8.

FIG. 8 illustrates an example embodiment where one gNB is acting as amaster gNB to handle the RIM related messages, in accordance withcertain embodiments. The master gNB may be a master victim gNB or amaster aggressor gNB, for example, based on a dynamic networkperformance. For example, the aggressor BS coordinates with a largenumber of victim BSs without incurring a large signaling load on thebackhaul. A master BS avoids incurring a large RIM coordinationsignaling load on the backhaul by using a centralized mechanism todistribute RIM coordination information between the BSs involved inremote interference, where the need for aggressor BS to establish adirect backhaul connection with every individual victim BS is avoided.

For the RIM coordination information exchange presented on non-limitingexamples of NG-RAN and NGC, where gNB is taken as an example of BS andAMF is an example of the MM node, from the aspect of aggressor BS, atstep 1, an aggressor gNB first learns from a RS received over the airinterface that it is causing interference to one or more victim gNBsbelonging to the same RSG. By detecting the RS sequence, the aggressorgNB learns the RSG identifier of the victim RSG, as well as theidentifier of the AMF of the victim gNB(s).

At step 2, the aggressor gNB then transmits, over the backhaul, a RIMcoordination message destined to the aggressor AMF. The RIM coordinationmessage contains, among other information, the identifier(s) of thevictim AMF and/or the identifier(s) of victim gNB(s) or gNB groups(e.g., the gNBs belonging to the same RSG identifies a gNB group). TheRIM coordination message first reaches the aggressor's AMF. In someembodiments, if the identifiers to the victim nodes (AMF, gNBs) are notexplicitly signaled, the information may be provided for the aggressor'sAMF to retrieve the needed information to reach the victim nodes (e.g.the victim AMF).

At step 3, based on the victim AMF identifier(s), the aggressor's AMFestablishes a path to the victim AMF(s) and passes to the victim AMF theRIM coordination message. In some embodiment, if a direct path is notestablished, the message may be routed, through intermediate corenetwork node(s), from the aggressor's AMF to the victims' AMF.

At step 4, upon reception of the RIM coordination message, the victimAMF determines, based on its available information, which of itsconnected victim gNBs belong to the RSG indicated in the RIMcoordination message.

At step 5, the victims' AMF then passes the RIM coordination message tothe victim gNB(s) or the victim gNB group (i.e., victim gNBs belongingto the RSG) indicated in the RIM coordination message. In particularembodiments where a master victim gNB is defined, the RIM coordinationmessage is only sent to the master victim gNB. The master victim gNBfurther sends the RIM coordination message to the other gNBs (e.g.,slave victim gNBs) via Xn interface.

Furthermore, for RIM coordination information exchange illustrated fromthe aspect of victim BS, at step 6, the victim gNBs send theirrespective RIM coordination messages to the victims' AMF.

At step 7, the victims' AMF collects the RIM coordination messagesincluding RIM information from the victim gNBs, and, based on the RIMinformation, assembles an aggregate RIM coordination message.

At step 8, the aggregate RIM coordination message is signaled back tothe aggressor's AMF from the victims' AMF. The aggressor's AMF passesthis information to the aggressor gNB or the aggressor gNB group (e.g.,aggressor gNBs belonging to the same RSG). In some embodiments, the RSGmay include a big set of gNBs. In some embodiments, the RSG may includea single gNB.

The full set of steps (e.g., steps 1 to 9) in the RIM coordinationinformation exchange need not necessarily be followed. For example, ifonly backhaul signaling between an aggressor gNB and a group ofreceiving victim gNBs is carried out, only steps 1 to 5 are used. Insome embodiments, the functionality described in the core network neednot be carried out by AMF, but could also, for example, be carried outby a newly defined node, solely defined for remote interferencemitigation purposes.

FIG. 9 illustrates an example network set, in accordance with certainembodiments. The network architecture shown in FIG. 9 illustrates asignaling between an AMF A and an AMF B. The AMF A associates withmultiple RSGs, for example, from RSG 1 to RSG N, and each RSG comprisesone or more BSs. Likewise, the AMF B associates with one or more RSGs(e.g., RSG 1 to RSG M), and each RSG comprises one or more BSs.

FIG. 10 illustrate an example signaling from an aggressor AMF to avictim AMF, in accordance with certain embodiments. The signaling insteps 1 to 5 are as shown in FIG. 10. Only the concerned/interfered RSGs(e.g., RSG 3 and RSG 6) are kept in FIG. 10.

In some embodiments, the victim gNBs inform their AMF that they arebeing interfered by an aggressor gNB. The AMF then selects one victimgNB that will send a RS to the aggressor gNBs, and invokes this victimgNB to transmit the RS which may be received by the aggressor gNBs,after which the communication proceeds as described herein.

In some embodiments, a group of aggressor gNBs situated in the same areareceives the RS transmitted by the victim gNBs. Each aggressor gNBassembles its respective RIM coordination message and sends it over thebackhaul to its respective AMF, i.e. aggressor AMF. The aggressor AMFaggregates these RIM coordination messages received from the aggressorgNBs and sends the aggregate RIM coordination message to the victims'AMF, after which the communication proceeds as described herein.

In some embodiments, one victim gNB collects all RIM coordinationinformation received from other victim gNBs over the Xn interfaceinstances and aggregates it into a single RIM coordination message andsends it to the victim AMF.

In some embodiments, the master aggressor gNB collects, from slaveaggressor gNBs, the information about RS received from victim gNBs, andis responsible for RIM coordination communication to the aggressor AMFas e.g. in step 1 above.

In some embodiments, the aggressor AMF may setup a “lightweight” NGapplication protocol (NGAP) signaling connection to the victim gNB onlyto convey the RIM coordination messages.

In some embodiments, the aggressor gNB may setup a “lightweight” NGAPsignaling connection to the victim AMF, only to convey the RIMcoordination messages.

In some embodiments, the aggressor gNB may write the RIM coordinationinformation into a database and send the address via backhaul to thevictim gNBs.

For reference signal content included in RS, different identifiers areembedded into the RS. For example, the RS may contain an explicitidentifier of the victims' AMF, e.g. AMF ID, AMF set ID, AMF region ID,or preconfigured index which can be a pointer to the AMF. In someembodiments, the RS may contain RSG ID, which implicitly points to theAMF affiliated to the victim gNBs.

In some embodiments, a mapping between RSG ID and the corresponding AMFsmay be in the form of a mapping table stored at the aggressor AMFs. Insome embodiments, the mapping may be retrieved by the aggressor AMF froma database, e.g. located in the core network. In some embodiments, themapping may be configured in the AMF nodes by the operations andmanagement (OAM) system.

In some embodiments, the RIM reference signal comprises two separateIDs, one AMF ID which directly or indirectly identifies the AMFassociated with the victim gNB(s), and one RSG ID which is an identifierthat may identify an individual or a group of gNBs associated with theAMF associated with the AMF ID.

The RSG ID may be allocated by the AMF to one or more of its associatedgNB arbitrarily. Therefore, only a certain AMF may know the mapping ofRSG ID to gNB IDs. When an aggressor gNB receives a RS with an AMF IDand RSG ID encoded into it, the aggressor gNB may transmit a message toits AMF over the backhaul, comprising these two IDs. The aggressor's AMFmay then look up which AMF the AMF ID corresponds to, and send a messageto that AMF comprising the RSG ID. Upon receiving such a message, thereceiving AMF looks up which gNB(s) correspond to the RSG ID andforwards the message to the gNB(s).

In some embodiment, the AMF ID and the RSG ID may jointly constitute aRIM-RS ID. For example, a 16-bit RIM-RS ID may be divided so that the 6MSBs constitute the AMF ID, while the 10 LSBs constitute the RSG ID. TheRIM-RS ID may then, for example, be encoded into the reference signaltransmission. For example, a 13-MSB RIM-RS ID may be encoded into thetime resource whereon the RS is transmitted, such as the frame numberand possibly additionally the slot or symbol within the frame. A 3-LSBRIM-RS ID may, for instance, be encoded in the choice of referencesignal sequence. For example, a pseudo-noise (PN) sequenceinitialization seed may depend on the 3-LSB RIM-RS ID.

In some embodiment, the RIM coordination message may comprise a gNB IDfor a source/destination address of a network node. Furthermore, the RIMcoordination message may further comprise a RSG ID for the receivingnetwork node, e.g., a gNB CU, to identify a recipient set of cells whichare interfered, e.g., a victim network nodes. In some embodiments, thereceiving network node may be a gNB or gNB-CU. A gNB CU manages a numberof gNB DUs, and each gNB DU manages a number of cells. In someembodiments, the gNB CU may be a monolith gNB which manages a number ofcells. When a RIM coordination message is sent from another gNB/gNB CU,the receiving gNB CU looks at the RSG ID, e.g., the destination set ID,checks its own records, and determines under which gNB-DUs are the cellsthat belong to the RSG ID. The receiving gNB CU may then forward the RIMcoordination message to determined gNB-DUs.

FIG. 11 illustrates an example telecommunication network connected viaan intermediate network to a host computer, in accordance with certainembodiments. With reference to FIG. 11, in accordance with anembodiment, a communication system includes telecommunication network1110, such as a 3GPP-type cellular network, which comprises accessnetwork 1111, such as a radio access network, and core network 1114.Access network 1111 comprises a plurality of base stations 1112 a, 1112b, 1112 c, such as NBs, eNBs, gNBs or other types of wireless accesspoints, each defining a corresponding coverage area 1113 a, 1113 b, 1113c. Each base station 1112 a, 1112 b, 1112 c is connectable to corenetwork 1114 over a wired or wireless connection 1115. A first UE 1191located in coverage area 1113 c is configured to wirelessly connect to,or be paged by, the corresponding base station 1112 c. A second UE 1192in coverage area 1113 a is wirelessly connectable to the correspondingbase station 1112 a. While a plurality of UEs 1191, 1192 are illustratedin this example, the disclosed embodiments are equally applicable to asituation where a sole UE is in the coverage area or where a sole UE isconnecting to the corresponding base station 1112.

Telecommunication network 1110 is itself connected to host computer1130, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 1130 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1121 and 1122 between telecommunication network 1110 andhost computer 1130 may extend directly from core network 1114 to hostcomputer 1130 or may go via an optional intermediate network 1120.Intermediate network 1120 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1120,if any, may be a backbone network or the Internet; in particular,intermediate network 1120 may comprise two or more sub-networks (notshown).

The communication system of FIG. 11 as a whole enables connectivitybetween the connected UEs 1191, 1192 and host computer 1130. Theconnectivity may be described as an over-the-top (OTT) connection 1150.Host computer 1130 and the connected UEs 1191, 1192 are configured tocommunicate data and/or signaling via OTT connection 1150, using accessnetwork 1111, core network 1114, any intermediate network 1120 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1150 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1150 passes areunaware of routing of uplink and downlink communications. For example,base station 1112 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1130 to be forwarded (e.g., handed over) to a connected UE1191. Similarly, base station 1112 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1191towards the host computer 1130.

FIG. 12 illustrates an example host computer communicating via a basestation with a user equipment over a partially wireless connection, inaccordance with certain embodiments. Example implementations, inaccordance with an embodiment, of the UE, base station and host computerdiscussed in the preceding paragraphs will now be described withreference to FIG. 12. In communication system 1200, host computer 1210comprises hardware 1215 including communication interface 1216configured to set up and maintain a wired or wireless connection with aninterface of a different communication device of communication system1200. Host computer 1210 further comprises processing circuitry 1218,which may have storage and/or processing capabilities. In particular,processing circuitry 1218 may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Host computer 1210 further comprises software 1211, whichis stored in or accessible by host computer 1210 and executable byprocessing circuitry 1218. Software 1211 includes host application 1212.Host application 1212 may be operable to provide a service to a remoteuser, such as UE 1230 connecting via OTT connection 1250 terminating atUE 1230 and host computer 1210. In providing the service to the remoteuser, host application 1212 may provide user data which is transmittedusing OTT connection 1250.

Communication system 1200 further includes base station 1220 provided ina telecommunication system and comprising hardware 1225 enabling it tocommunicate with host computer 1210 and with UE 1230. Hardware 1225 mayinclude communication interface 1226 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 1200, as well as radiointerface 1227 for setting up and maintaining at least wirelessconnection 1270 with UE 1230 located in a coverage area (not shown inFIG. 12) served by base station 1220. Communication interface 1226 maybe configured to facilitate connection 1260 to host computer 1210.Connection 1260 may be direct or it may pass through a core network (notshown in FIG. 12) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 1225 of base station 1220 further includesprocessing circuitry 1228, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 1220 further has software 1221 storedinternally or accessible via an external connection.

Communication system 1200 further includes UE 1230 already referred to.Its hardware 1235 may include radio interface 1237 configured to set upand maintain wireless connection 1270 with a base station serving acoverage area in which UE 1230 is currently located. Hardware 1235 of UE1230 further includes processing circuitry 1238, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 1230 further comprisessoftware 1231, which is stored in or accessible by UE 1230 andexecutable by processing circuitry 1238. Software 1231 includes clientapplication 1232. Client application 1232 may be operable to provide aservice to a human or non-human user via UE 1230, with the support ofhost computer 1210. In host computer 1210, an executing host application1212 may communicate with the executing client application 1232 via OTTconnection 1250 terminating at UE 1230 and host computer 1210. Inproviding the service to the user, client application 1232 may receiverequest data from host application 1212 and provide user data inresponse to the request data. OTT connection 1250 may transfer both therequest data and the user data. Client application 1232 may interactwith the user to generate the user data that it provides.

It is noted that host computer 1210, base station 1220 and UE 1230illustrated in FIG. 12 may be similar or identical to host computer1130, one of base stations 1112 a, 1112 b, 1112 c and one of UEs 1191,1192 of FIG. 11, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 12 and independently, thesurrounding network topology may be that of FIG. 11.

In FIG. 12, OTT connection 1250 has been drawn abstractly to illustratethe communication between host computer 1210 and UE 1230 via basestation 1220, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 1230 or from the service provider operating host computer1210, or both. While OTT connection 1250 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 1270 between UE 1230 and base station 1220 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 1230 using OTT connection1250, in which wireless connection 1270 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the handlingof redundant data in the transmit buffer and thereby provide benefitssuch as improved efficiency in radio resource use (e.g., nottransmitting redundant data) as well as reduced delay in receiving newdata (e.g., by removing redundant data in the buffer, new data can betransmitted sooner).

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 1250 between hostcomputer 1210 and UE 1230, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 1250 may be implemented in software 1211and hardware 1215 of host computer 1210 or in software 1231 and hardware1235 of UE 1230, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 1250 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 1211, 1231 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 1250 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 1220, and it may be unknownor imperceptible to base station 1220. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 1210's measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 1211 and 1231 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 1250 while it monitors propagation times, errors etc.

FIG. 13 illustrates an example method implemented in a communicationsystem including a host computer, a base station and a user equipment,in accordance with certain embodiments. More specifically, FIG. 13 is aflowchart illustrating a method implemented in a communication system,in accordance with one embodiment. The communication system includes ahost computer, a base station which may be a network node described withreference to FIG. 18. For simplicity of the present disclosure, onlydrawing references to FIG. 13 will be included in this section. In step1310, the host computer provides user data. In substep 1311 (which maybe optional) of step 1310, the host computer provides the user data byexecuting a host application. In step 1320, the host computer initiatesa transmission carrying the user data to the UE. In step 1330 (which maybe optional), the base station transmits to the UE the user data whichwas carried in the transmission that the host computer initiated, inaccordance with the teachings of the embodiments described throughoutthis disclosure. In step 1340 (which may also be optional), the UEexecutes a client application associated with the host applicationexecuted by the host computer.

FIG. 14 illustrates an example method implemented in a communicationsystem including a host computer, a base station and a user equipment,in accordance with some embodiments. More specifically, FIG. 14 is aflowchart illustrating a method implemented in a communication system,in accordance with one embodiment. The communication system includes ahost computer, a base station which may be a network node described withreference to FIG. 18. For simplicity of the present disclosure, onlydrawing references to FIG. 14 will be included in this section. In step1410 of the method, the host computer provides user data. In an optionalsubstep (not shown) the host computer provides the user data byexecuting a host application. In step 1420, the host computer initiatesa transmission carrying the user data to the UE. The transmission maypass via the base station, in accordance with the teachings of theembodiments described throughout this disclosure. In step 1430 (whichmay be optional), the UE receives the user data carried in thetransmission.

FIG. 15 illustrates another further example method implemented in acommunication system including a host computer, a base station and auser equipment, in accordance with certain embodiments. Morespecifically, FIG. 15 is a flowchart illustrating a method implementedin a communication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station which maybe a network node described with reference to FIG. 18. For simplicity ofthe present disclosure, only drawing references to FIG. 15 will beincluded in this section. In step 1510 (which may be optional), the UEreceives input data provided by the host computer. Additionally oralternatively, in step 1520, the UE provides user data. In substep 1521(which may be optional) of step 1520, the UE provides the user data byexecuting a client application. In substep 1511 (which may be optional)of step 1510, the UE executes a client application which provides theuser data in reaction to the received input data provided by the hostcomputer. In providing the user data, the executed client applicationmay further consider user input received from the user. Regardless ofthe specific manner in which the user data was provided, the UEinitiates, in substep 1530 (which may be optional), transmission of theuser data to the host computer. In step 1540 of the method, the hostcomputer receives the user data transmitted from the UE, in accordancewith the teachings of the embodiments described throughout thisdisclosure.

FIG. 16 illustrates another example method implemented in acommunication system including a host computer, a base station and auser equipment, in accordance with certain embodiments. Morespecifically, FIG. 16 is a flowchart illustrating a method implementedin a communication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UE.In one embodiment, the base station may be a network node described withreferences to FIG. 18. For simplicity of the present disclosure, onlydrawing references to FIG. 16 will be included in this section. In step1610 (which may be optional), in accordance with the teachings of theembodiments described throughout this disclosure, the base stationreceives user data from the UE. In step 1620 (which may be optional),the base station initiates transmission of the received user data to thehost computer. In step 1630 (which may be optional), the host computerreceives the user data carried in the transmission initiated by the basestation.

FIG. 17 illustrates a flow diagram of an example method, in accordancewith certain embodiments. The method may be performed by a network node.The network node may be the network node 460 depicted in FIG. 4. Method1700 begins at step 1710 with receiving, from a first network node, areference signal indicating that one or more second network nodes areexperiencing interference. In some embodiments, the reference signal mayindicate at least one identifier for the first network node and for theone or more second network nodes. In some embodiments, the one or moresecond network nodes may belong to a same reference signal group (RSG).In some embodiments, the first network node may be a central unit (CU)and the one or more second network nodes may be a group of distributedunits (DUs). The first network node may be a master network node of theone or more second network nodes. In some embodiments, the first networknode may an Access and Mobility Management Function (AMF) node. In someembodiments, the first network node and the one or more second networknodes may be victim network nodes.

At step 1720, the method 1700 prepares a remote interference management(RIM) coordination message based on the reference signal. In someembodiments, preparing the RIM coordination message may comprisetransmitting, to a third network node, the RIM coordination message overbackhaul, aggregating, at the third network node, the RIM coordinationmessage transmitted over backhaul, and identifying, at the third networknode, a first identifier for the first network node and a secondidentifier for the one or more second network nodes based on thereference signal. In some embodiments, the first identifier and thesecond identifier are included in the RIM coordination messageaggregated at the third network node. In some embodiments, identifyingthe first identifier for the first network node and the secondidentifier for the one or more second network nodes may compriseretrieving, at the third network node, mapping information from adatabase in a core network. The mapping information comprises a mappingbetween the first identifier and the second identifier. In someembodiments, the second network node is an AMF node. In someembodiments, the second network node may be an aggressor network node.In some embodiments, the first identifier for the first network node maybe an AMF ID, an AMF set ID, an AMF region ID, or a preconfigured indexwhich indicates the first network node. In some embodiments, the secondidentifier for the one or more second network nodes may a RSG ID whichidentifies an individual network node or a group of network nodesassociated with the first network node associated with the firstidentifier.

At step 1730, the method 1700 sends, to the first network node, the RIMcoordination message to be forwarded to the one or more second networknodes. In some embodiments, the method 1700 may further forward, fromthe first network node to the one or more second network nodes, the RIMcoordination message over Xn interface at step 1740. In someembodiments, sending the RIM coordination message may compriseestablishing a connection with the first network node, sending the RIMcoordination message to the first network node over backhaul, andforwarding the RIM coordination message to the one or more secondnetwork nodes via the Xn interface. In some embodiments, the connectionmay be a route via an intermediate network node in a core network.

FIG. 18 is a schematic block diagram of an exemplary network node 1800in a wireless network, in accordance with certain embodiments. In someembodiments, the wireless network may be the wireless network 406 shownin FIG. 4. The network node may be the network node 460 shown in FIG. 4.The network node 1800 is operable to carry out the example methoddescribed with reference to FIG. 17 and possibly any other processes ormethods disclosed herein. It is also to be understood that the methodsin FIG. 17 is not necessarily carried out solely by the network node1800. At least some operations of the method can be performed by one ormore other entities.

Network node 1800 may comprise processing circuitry, which may includeone or more microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. In some embodiments, theprocessing circuitry of the network node 1800 may be the processingcircuitry 470 shown in FIG. 4. The processing circuitry may beconfigured to execute program code stored in memory, which may includeone or several types of memory such as read-only memory (ROM),random-access memory, cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein, in several embodiments. In someimplementations, the processing circuitry may be used to cause receivingunit 1810, preparing unit 1820, sending unit 1830, and any othersuitable units of network node 1800 to perform corresponding functionsaccording one or more embodiments of the present disclosure, such as aprocessor, a receiver, and a transmitter.

As illustrated in FIG. 18, the network node 1800 includes the receivingunit 1810, the preparing unit 1820, and the sending unit 1830. Thereceiving unit 1810 may be configured to receive, from a first networknode, a reference signal indicating that one or more second networknodes are experiencing interference. In some embodiments, the referencesignal may indicate at least one identifier for the first network nodeand for the one or more second network nodes. In some embodiments, theone or more second network nodes may belong to a same reference signalgroup (RSG). In some embodiments, the first network node may be a CU andthe one or more second network nodes may be a group of DUs. The firstnetwork node may be a master network node of the one or more secondnetwork nodes. In some embodiments, the first network node may an AMFnode. In some embodiments, the first network node and the one or moresecond network nodes may be victim network nodes.

The preparing unit 1820 may be configured to prepare a RIM coordinationmessage based on the reference signal. In some embodiments, thepreparing unit 1820 may be configured to transmit, to a third networknode, the RIM coordination message over backhaul, aggregate, at thethird network node, the RIM coordination message transmitted overbackhaul, and identify, at the third network node, a first identifierfor the first network node and a second identifier for the one or moresecond network nodes based on the reference signal. In some embodiments,the first identifier and the second identifier are included in the RIMcoordination message aggregated at the third network node. In someembodiments, the preparing unit 1820 may further be configured toretrieve, at the third network node, mapping information from a databasein a core network. The mapping information comprises a mapping betweenthe first identifier and the second identifier. In some embodiments, thesecond network node is an AMF node. In some embodiments, the secondnetwork node may be an aggressor network node. In some embodiments, thefirst identifier for the first network node may be an AMF ID, an AMF setID, an AMF region ID, or a preconfigured index which indicates the firstnetwork node. In some embodiments, the second identifier for the one ormore second network nodes may a RSG ID which identifies an individualnetwork node or a group of network nodes associated with the firstnetwork node associated with the first identifier.

The sending unit 1830 may be configured to send, to the first networknode, the RIM coordination message to be forwarded to the one or moresecond network nodes. In some embodiments, the sending unit 1830 may beconfigured to establish a connection with the first network node, sendthe RIM coordination message to the first network node over backhaul,and forward the RIM coordination message to the one or more secondnetwork nodes via a Xn interface. In some embodiments, the connectionmay be a route via an intermediate network node in a core network.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, receivers, transmitters, memories, logic solid state and/ordiscrete devices, computer programs or instructions for carrying outrespective tasks, procedures, computations, outputs, and/or displayingfunctions, and so on, as such as those that are described herein.

According to various embodiments, an advantage of features herein isthat a central network node may coordinate reference signals from itsgroup of network nodes and communicate with another central network nodevia the backhaul to exchange the reference signals and the RIM-relatedmessage, such that a large signaling load in the network can be avoided.In addition, another advantage of features herein is that providing ascalable solution specific to the interferences caused by an aggressornetwork node in the distance. Particular embodiments of the presentapplication allow the central network node to identify its group ofnetwork nodes based on the identifier included in the RIM-relatedmessages, such that the central network node may then forward theRIM-related message to the identified network nodes to improve networkperformance.

While processes in the figures may show a particular order of operationsperformed by certain embodiments of the invention, it should beunderstood that such order is exemplary (e.g., alternative embodimentsmay perform the operations in a different order, combine certainoperations, overlap certain operations, etc.).

While the invention has been described in terms of several embodiments,those skilled in the art will recognize that the invention is notlimited to the embodiments described, can be practiced with modificationand alteration within the spirit and scope of the appended claims. Thedescription is thus to be regarded as illustrative instead of limiting.

1. A method for interference coordination, comprising: receiving, from afirst network node, a reference signal indicating that one or moresecond network nodes are experiencing interference, wherein thereference signal indicates at least one identifier for the first networknode and for the one or more second network nodes; preparing a remoteinterference management (RIM) coordination message based on thereference signal; and sending, to the first network node, the RIMcoordination message to be forwarded to the one or more second networknodes.
 2. The method according to claim 1, wherein the first networknode is a central unit and the one or more second network nodes are agroup of distributed units.
 3. The method according to claim 1, whereinthe first network node is an Access and Mobility Management Function(AMF) node.
 4. The method according to claim 1, wherein sending the RIMmessage comprises: establishing a connection with the first networknode; sending the RIM coordination message to the first network nodeover backhaul; and forwarding the RIM coordination message to the one ormore second network nodes via a Xn interface.
 5. The method according toclaim 4, wherein the connection is a route via an intermediate networknode in a core network.
 6. The method according to claim 1, whereinpreparing the RIM coordination message comprises: transmitting, to athird network node, the RIM coordination message over backhaul;aggregating, at the third network node, the RIM coordination messagetransmitted over backhaul; and identifying, at the third network node, afirst identifier for the first network node and a second identifier forthe one or more second network nodes based on the reference signal,wherein the first identifier and the second identifier are included inthe RIM coordination message aggregated at the third network node. 7.The method according to claim 6, wherein identifying the firstidentifier for the first network node and the second identifier for theone or more second network nodes comprises: retrieving, at the thirdnetwork node, mapping information from a database in a core network,wherein the mapping information comprises a mapping between the firstidentifier and the second identifier.
 8. The method according to claim6, wherein the third network node is an AMF node.
 9. The methodaccording to claim 6, wherein the first identifier for the first networknode is an AMF identifier (ID), an AMF set ID, an AMD region ID, or apreconfigured index which indicates the first network node.
 10. Themethod according to claim 6, wherein the second identifier for the oneor more second network nodes is a reference signal group (RSG) ID whichidentifies an individual network node or a group of network nodesassociated with the first network node associated with the firstidentifier.
 11. A network node for positioning reference signalconfiguration, comprising: at least one processing circuitry; and atleast one storage that stores processor-executable instructions, whenexecuted by the processing circuitry, causes a network node to: receive,from a first network node, a reference signal indicating that one ormore second network nodes are experiencing interference, wherein thereference signal indicates at least one identifier for the first networknode and for the one or more second network nodes; prepare a remoteinterference management (RIM) coordination message based on thereference signal; and send, to the first network node, the RIMcoordination message to be forwarded to the one or more second networknodes.
 12. The network node according to claim 11, wherein the firstnetwork node is a central unit and the one or more second network nodesare a group of distributed units.
 13. The network node according toclaim 11, wherein the first network node is an Access and MobilityManagement Function (AMF) node.
 14. The network node according to claim11, wherein sending the RIM message comprises: establishing a connectionwith the first network node; and sending the RIM coordination message tothe first network node over backhaul, wherein the RIM coordinationmessage is further to be forwarded to the one or more second networknodes via a Xn interface.
 15. The network node according claim 14,wherein the connection is a route via an intermediate network node in acore network.
 16. The network node according to claim 11, whereinpreparing the RIM coordination message comprises: transmitting, to athird network node, the RIM coordination message over backhaul;aggregating, at the third network node, the RIM coordination messagetransmitted over backhaul; and identifying, at the third network node, afirst identifier for the first network node and a second identifier forthe one or more second network nodes based on the reference signal,wherein the first identifier and the second identifier are included inthe RIM coordination message aggregated at the third network node. 17.The network node according to claim 16, wherein identifying the firstidentifier for the first network node and the second identifier for theone or more second network nodes comprises: retrieving, at the thirdnetwork node, mapping information from a database in a core network,wherein the mapping information comprises a mapping between the firstidentifier and the second identifier; and sending, from the thirdnetwork node to the first network node, the RIM coordination message.18. The network node according to claim 16, wherein the third networknode is an AMF node.
 19. The network node according to claim 16, whereinthe first identifier for the first network node is an AMF identifier(ID), an AMF set ID, an AMF region ID, or a preconfigured index whichindicates the first network node.
 20. The network node according toclaim 16, wherein the second identifier for the one or more secondnetwork nodes is a reference signal group (RSG) ID which identifies anindividual network node or a group of network nodes associated with thefirst network node associated with the first identifier.